Laptop PC Buyer's Guide Tips On What To Look At When Considering Buying A Laptop

Laptop PC Buyer's Guide
Tips On What To Look At When Considering Buying A Laptop
Laptop systems have grown in popularity due to their increasing performance and portability. For many people, they offer more than enough performance and features that they have completely replaced the need for a desktop computer. This guide will help you to look at some of the key items you want to look at before you purchase your next PC laptop system.
Size and Weight
Obviously the size and weight of a laptop is important. Ultrathin laptops such as Ultrabooks may be extremely portable but often lack a few features. Desktop replacements have equivalent power to desktop systems but they are heavy and bulky making them difficult to carry around. When shopping for a laptop, make sure to pick up the systems and verify its something you are willing to carry. Don't forget to also consider the weight of accessories such as AC adapter when carrying around the laptop.
Processors (CPU)
Mobile processors typically were slower than desktop CPUs but they still are fast enough for what most people need. Dual-core processors are typical now with quad core models available for those looking for better multitasking. The type of processors found in the laptop will vary based upon the size and purpose of the laptop. They have a direct impact on performance as well as battery life so comparison can be difficult. It should be noted that most ultrabooks use a lower speed processor to try and conserve power which can impact those looking to do more demanding tasks. Check out my listings for suggested processors for the various types of laptop PCs available.
Memory (RAM)
Laptops are generally more restricted in the amount of memory they can have compared to desktops. When looking at computers you want to make sure to check out the maximum memory the system can handle as well as the amount that is installed in the computer. It is also useful to find out if a memory upgrade can be done yourself or if it has to be done by a technician. Four gigabytes should really be the minimum amount of memory to consider with 8GB for improved performance.
Displays and Video
The video on a laptop computer is comprised of the display and the video processor. The display is defined by the screen size and the native resolution. The larger the display, the higher the resolution will typically be but it also will impact how portable the system is. The graphics processor will determine the performance of the computer in things such as 3D gaming or for accelerating non-3D applications.
Data Storage
How much storage space will you need? Hard drives are fairly straight forward in terms of the size and the performance may be impacted by the rotational speed. More and more laptops are opting to use the faster and more durable solid state drives even if they offer less overall capacity. Optical drives are becoming less important for laptop computers such that many do not even have them. Blu-ray is available for viewing high definition video but are still fairly uncommon.
The ability to connect to the net is integral to most laptops today. Pretty much every laptop comes with some form of Wi-Fi built in with the 802.11b/g/n being the most common. Wired networking is still available on many with Gigabit Ethernet being the most typical speed supported. Bluetooth is useful for wireless peripherals and for those that need connectivity in remote locations, a built-in modem or a cellular (WWAN) card are also options.
Battery Life
How good is a portable computer going to be if you are only able to get a couple of hours computing time on a single charge? Some systems may advertise all day computing which really translates into almost eight hours which is the typical length of a working day but most are much lower. Try to find the manufacturer's listed battery life for the standard battery. Look to get a system with at least three to four hours of battery life under normal conditions for higher performance. More portable ultrabook systems should have at least six hours. If you need extended time unplugged, look for laptops with media bays that can double as extra battery slots or have extended life batteries that can be purchased.
Warranty Plans
Laptops take a lot of abuse and are more prone to breakdowns due to their portability. When buying a system, make sure to get at least a one year warranty from the manufacturer. If you will be using the system heavily, a system that comes with a two or three year warranty might be a better choice but it will cost more. Third party extended plans are not a good choice unless service is done through the manufacturer.

LCD Monitor Buyer's Guide How to Compare LCD Monitors Based on Specifications To Find The Right One

LCD Monitor Buyer's Guide
How to Compare LCD Monitors Based on Specifications To Find The Right One
With manufacturing improving, LCD panel sizes continue to get larger all while prices keep dropping. Retailers and manufacturers throw around a lot of numbers and terms to describe their products. So, how does one know what all these mean? This article looks to cover the basics so one can make an informed decision when buying an LCD monitor.
Screen Size
The screen size is the measurement of the displayable area of the screen from the lower corner to the opposite upper corner of the display. LCD's typically gave their actual measurements but they are now rounding those numbers. Be sure to find the real dimensions typically referred to as the actual screen size whenever looking at a LCD. For example, a display with a 23.6-inch actual size screen may be marketed as either a 23-inch or a 24-inch display.
Aspect Ratio
The aspect ratio refers to the number of horizontal pixels to vertical pixels in a display. In the past, monitors used the same 4:3 aspect ratio as televisions. Most new monitors use either a 16:10 or 16:9 widescreen aspect ratio. The 16:9 is the ratio typically used for HDTVs and is now the most common. There are even a few ultra wide or 21:9 aspect ratio monitors on the market but they aren't very common.
Native Resolutions
All LCD screens can actually display only a single given resolution referred to as the native resolution. This is the physical number of horizontal and vertical pixels that make up the LCD matrix of the display. Setting a computer display to a resolution lower than this will cause extrapolation. This extrapolation attempts to blend multiple pixels together to produce an image to fill the screen as if it were at the native resolution but it can result in images that appear a bit fuzzy.
Here are some of the common native resolutions found in LCD monitors:
21" (Widescreen): 1920x1080 (WUXGA)
22" (Widescreen): 1920x1080 (WUXGA)
24" (Widescreen): 1920x1080 (WUXGA)
27" (Widescreen): 2560x1440 (WQHD)
30" (Widescreen): 2560x1600 (WQXGA)
30+" (Widescreen): 3840x2160 or 4096x2160 (UHD or 4K)
These are just typical native resolutions. There are smaller 24-inch monitors that feature the 4K resolutions and there are many 27-inch displays that feature the 1080p resolutions. Just be aware that higher resoltuions on smaller displays can make text difficult to read athte typical viewing distance.
Panel Coatings
This is something that most people don't think about much primarily because the market may not give them a choice. The coatings of the display panel fall into two categories: glossy or anti-glare (matte). The majority of monitors for consumers use a glossy coating. This is done because it tends to show off colors better in low light conditions. The downside is that when used under bright light it generates glare and reflections. You can tell most monitors with glossy coatings either through the use of glass on the outside front of the monitor or through terms such as crystal to describe the filters. Business oriented monitors tend to come with anti-glare coatings. These have a film over the LCD panel that helps reduces reflections. It will slightly mute the colors but they are much better in bright lighting conditions such as offices with overhead flourescent lighting.
A good way to tell which type of coating will work best for your LCD monitor is to do a small test where the display is going to be used. Take a small piece of glass such as a picture frame and place it where the monitor would be and set the lighting how it will be when the computer is used. If you see a lot of reflections or glare off the glass, it is best to get an anti-glare coated screen. If you don't have the reflections and glare, then a glossy screen will work fine.
Contrast Ratio
Contrast ratios are a big marketing tool by the manufacturers and one that is not easy for consumers to grasp. Essentially, this is the measurement of the difference in brightness from the darkest to brightest portion on the screen. The problem is that this measurement will vary throughout the screen. This is due to the slight variations in the lighting behind the panel. Manufacturers will use the highest contrast ratio they can find on a screen, so it is very deceptive. Basically a higher contrast ratio will mean that the screen will tend to have deeper blacks and brighter whites. Look for the typical contrast ratio which is around 1000:1 rather than dynamic numbers that is often in the millions to one.
Color Gamut
Each LCD panel will vary slightly in how well they can reproduce color. When an LCD is being used for tasks that require a high level of color accuracy, it is important to find out what the panel's color gamut is. This is a description that lets you know how wide a range of color the screen can display. The larger the percentage coverage of a specific gamut, the greater level of color a monitor can display. It is somewhat complex and best described in my article on Color Gamuts. Most basic consumers LCDs range from 70 to 80 percent of NTSC.
Response Times
In order to achieve the color on a pixel in an LCD panel, a current is applied to the crystals at that pixel to change the state of the crystals. Response times refer to the amount of time it takes for the crystals in the panel to move from an on to off state. A rising response time refers to the amount of time it takes to turn on the crystals and the falling time is the amount of time it takes for the crystals to move from an on to off state. Rising times tend to be very fast on LCDs, but the falling time tends to be much slower. This tends to cause a slight blurring effect on bright moving images on black backgrounds. It is often time referred to as ghosting. The lower the response time, the less of a blurring effect there will be on the screen. Most response times now refer to a gray to gray rating that generates a lower number than the traditional full on to off state response times.
Viewing Angles
LCD's produce their image by having a film that when a current runs through the pixel, it turns on that shade of color. The problem with the LCD film is that this color can only be accurately represented when viewed straight on. The further away from a perpendicular viewing angle, the color will tend to wash out. The LCD monitors are generally rated for their visible viewing angle for both horizontal and vertical. This is rated in degrees and is the arc of a semicircle whose center is at the perpendicular to the screen. A theoretical viewing angle of 180 degrees would mean that it is fully visible from any angle in front of the screen. A higher viewing angle is preferred over a lower angle unless you happen to want some security with your screen. Note that the viewing angles still may not translate fully to a good quality image but one that is viewable.
Most LCD panels use digital connectors now but some still feature an analog one. The analog connector is the VGA or DSUB-15. HDMI is now the most common digital connector thanks to its adoption in HDTVs. DVI was previously the most popular computer digital interface but is starting to be dropped from many desktops and almost never found on laptops. DisplayPort and its mini version are now becoming more popular for high end graphics displays. Thunderbolt is Apple and Intel's new connector that is fully compatible with the DisplayPort standards but can also carry other data as well. Check to see what type of connector your video card can use before buying a monitor to ensure you get a compatible monitor. You still may be able to use a monitor with a different connector than your video card by using adapters but they can get fairly expensive. Some monitors may also come with home theater connectors including component, composite and S-video but this again is becoming extremely uncommon due to HDMI's ubiquity.
Refresh Rates And 3D Displays
Consumer electronics have been trying to push 3D HDTV's very heavily but consumers are not really catching on yet. There is a small market for 3D displays for computers thanks to PC gamers that want a bit more immersive environments. The primary requirement for a 3D display is to have a 120Hz panel. This is double the refresh rate of a traditional display in order to provide alternating images for each of the eyes to simulate 3D. In addition to this, most 3D displays have to be desiged to work with NVIDIA's 3D Vision or AMD's HD3D. These are various implementations of active shutter glasses with an IR transmitter. Some monitors will have the transmitters built into the display thus only requiring the glasses while others will need a seperate 3D kit to be purchased in order for the 3D displays to function in a 3D mode.
Touchscreen monitors are a fairly new item to the desktop marketplace. While touchscreens are very popular for laptops thanks to Windows 8, they are still uncommon in stand alone monitors. The primary reason for this has to do with the cost of implementing the touch interface across a large screen. There are two types of touch interfaces used: capacitive and optical. Capacitive is the most common type used in tablets and laptops because it is very fast and accurate. The problem is that it is very expensive to produce the capactive surface to cover the large display. As a result, most touch monitors use optical technology. This uses a series of infrared light sensors that reside just in front the screen causing a raised bezel edge around the display screen. They do work and can support up to ten point multitouch but they tend to be a bit slower.
All stand alone touchscreen displays will use some form of USB to connect to the computer for transmitting the positional input data for the touchscreen.
Many people don't consider the stand when purchasing a monitor but it can make a huge difference. There are typically four different types of adjustment: height, tilt, swivel and pivot. Many less expensive monitors only feature the tilt adjustment. Height, tilt and swivel are generally the critical types of adjustments allowing for the greatest flexibility when using the monitor in the most ergonmoic fashion.

Tablets vs. Laptops Should You Buy A Tablet Instead Of A Laptop?

Tablets vs. Laptops
Should You Buy A Tablet Instead Of A Laptop?
Tablets have become quite popular thanks to their extreme portability, easy to use interfaces and the wide range of ways they can be used. In many ways, they can almost replace a laptop for someone on the go. But is a tablet really a better choice for someone over a more traditional laptop? After all, laptops can also be extremely portable and have a much wider range of tasks they can be used for.
In this article, I'm going to take a look at the various differences between tablets and laptops to see how they compare to one another and which of the two may be better. By examining these in more detail, one can then have a clearer understanding of which of these two types of mobile computing platforms would serve them better.
Input Method
The most obvious difference between a tablet and a laptop is the lack of a keyboard. Tablet's rely solely on a touch interface on the screen for all input. This is fine when it involves mainly pointing, dragging or tapping to navigate around a program. The problems come in when you have to input text into a program when such as an email or document. Since they have no keyboard, users are required to type on virtual keyboards that have varying layouts and designs. Most people cannot type type as quickly or as accurately on a virtual keyboard. Users do have the option of adding an external Bluetooth keyboard to most tablets to make this more like a laptop but it adds costs and peripherals that must be taken with the tablet.
Result: Laptops for those that write a lot, tablets for those that do more point interaction.
This is probably the biggest reason to go with a tablet compared to a laptop. Tablets have the size roughly of a small pad of paper and a weight that is under two pounds. Most laptops are far larger and heavier. Even one of the smallest ultraportables, the Apple MacBook Air 11 weighs just over two pounds and has a profile that is larger than an iPad 2. The main reason for this is the keyboard and trackpad which require it to be larger. Add in more powerful components that require additional cooling and power and they get even larger. Because of this, it is much easier to carry around a tablet than a laptop especially if you happen to be traveling.
Result: Tablets
Battery Life
Tablets are design for efficiency because of the low power requirements of their hardware components. In fact, the majority of the interior of a tablet is taken up by the battery. In comparison, laptops use more powerful hardware. The battery component of the laptop is a far smaller percentage of the laptops internal components. Thus, even with the higher capacity battery of laptops, they do not run as long as a tablet. Many of the tablets right now can run up to ten hours of web usage before require a charge. The average laptop would only run for roughly three to four hours with a few systems able to stretch it out to eight hours but that still less than a tablet. This means that tablets can achieve all day usage which few laptops can achieve.
Result: Tablets
Storage Capacity
In order to keep their size and costs down, tablets have had to rely on new solid state storage memory as a means to store programs and data. While these have the potential for faster access and low power usage, they have one major disadvantage in the amount of files they can store. Most tablets come with configurations that allow between 16 and 64 gigabytes of storage. By comparison, most laptops still use traditional hard drives that hold far much more. Extremely affordable netbooks still have 160 gigabytes of storage which allows for ten times the amount of data as the most affordable tablets. This won't always be the case though as some laptops have moved to solid state drives as well and may have as little as 64GB of space.
Result: Laptops
Since most tablets are based on extremely low powered processors, they will generally fall behind a laptop when it comes to computing tasks. Of course, a lot of this will depend on how the tablet or laptop is being used. For tasks like email, web browsing, playing video or audio, both platforms will typically work just as well as neither requires much performance. Things get more complicated once you start doing more demanding tasks. For the most part, multitasking or graphics performance it typically better suited with a laptop but not always. Take for instance video editing. One would assume that this would always be in the laptops favor but a recent test of video editing on the iPad 2 with iMovie found its specialized video hardware actually provided higher performance than doing the same task with iMovie on a MacBook Pro. The difference is the laptop version has more capabilities which brings us to the next item to consider...
Result: Laptops
The software that runs on a laptop or tablet can be vastly different in terms of capabilities. Now if the tablet PC is running Windows 7 such as the HP Slate or ASUS Eee Slate it can theoretically run the same software as a laptop but will likely be slower. This can make it easy to use it as a primary laptop using the same software used in a work environment. The two other major tablet platforms right now are Android and iOS. Both of these require applications specific to their operating systems. There are tons of programs available for each of these and many will do most of the basic tasks that a laptop can do. The problem is the lack of the input devices and hardware performance limitations mean that some more advanced features supplied by corresponding laptop class programs may have to be dropped in order to fit into the tablet environment.
Result: Laptops
Tablets are relatively new to the market and as a result, they tend to carry a fairly high price premium for the new technologies they have installed in them. The average starting price for a tablet seems to have settled around $499. By comparison, there are laptop computers that can be found for as little as $300 to $400. Of course, most people are probably not going to be looking at the least expensive laptop. The average price of the laptop is more around $650 which is slightly more expensive than the mid range tablet cost. Laptops still have the advantage over tablets though if you look at equivalent performance and features. After all, netbooks start below $300 but can generally handle all the same tasks as a tablet, just in a not as easy to carry or use format.
Result: Tie
Stand Alone Device
This category is describing a situation where a tablet would be your only computer system. It isn't something that many people would necessarily think about when looking at the devices but it is pretty critical. A laptop is a fully self contained system that one can use fully as a computer system in terms of loading data and programs onto and backing up. Many tablets actually require an additional computer system beyond the tablet for backing up the device or even activating it. The iPad 2 is a good example of this as the first thing a user is required to do is hook it up to a PC to activate it. Now, one could do this on another person's computer but you still have the problem of backing up data especially if you want to temporarily remove an application if you have limited space.
Result: Laptop
As it stands, laptops still offer a greater level of flexibility when it comes to mobile computing. They may not have the same level of portability, running times or ease of use of a tablet but there are still a number of issues that tablets need to resolve before they become the main means of mobile computing. Over time, many of these issues will likely be resolved. If you already have a desktop computer, than a tablet may be an option if you use it mainly for entertainment and web usage. If it is going to be your primary computer, than a laptop is definitely the way to go.

എല്ലാം ഫ് ളെക്‌സിബിളാകുന്ന കാലം ഇലക്ട്രോണിക് ഉപകരണങ്ങളെ വളയ്ക്കാം, മടക്കാം, പേപ്പറുകള്‍ ചുരുട്ടി വയ്ക്കുന്നതുപോലെ ചുരുട്ടാം, ഇലാസ്‌ററിക് പോലെ വലിച്ച് നീട്ടാം - ഇതൊക്കെ ഭാവിയില്‍ സാധാരണമാകാന്‍ പോവുകയാണ്

എല്ലാം ഫ് ളെക്‌സിബിളാകുന്ന കാലം
ഇലക്ട്രോണിക് ഉപകരണങ്ങളെ വളയ്ക്കാം, മടക്കാം, പേപ്പറുകള്‍ ചുരുട്ടി വയ്ക്കുന്നതുപോലെ ചുരുട്ടാം, ഇലാസ്‌ററിക് പോലെ വലിച്ച് നീട്ടാം - ഇതൊക്കെ ഭാവിയില്‍ സാധാരണമാകാന്‍ പോവുകയാണ്
എല്ലാം ഫ് ളെക്‌സിബിളായ ഇന്നത്തെ കാലത്ത് ഇലക്ട്രോണിക്‌സിന് മാത്രമായി മാറി നില്‍ക്കാനാകുമോ. അതുകൊണ്ട് സാധ്യതകളുടെ വിശാല പ്രപഞ്ചം തുറന്നിട്ടുകൊണ്ട് ഭാവിയുടെ സാങ്കേതികവിദ്യ ആവുകയാണ് ഇപ്പോള്‍ ഇലക്ട്രോണിക്‌സ് മേഖല. ഇലക്ട്രോണിക്‌സ് എന്ന് മാത്രം പറഞ്ഞാല്‍ പൂര്‍ത്തിയാകില്ല. ഫ് ളക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സ് എന്ന് തികച്ച് പറയണം.
എന്താണ് ഈ ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സ് എന്ന് ചോദിക്കുന്നതിനേക്കാള്‍ എന്തല്ല എന്ന് ചോദിക്കുന്നതാണ് ഉചിതം. കളിക്കോപ്പ് മുതല്‍ പടക്കോപ്പ് വരെ വ്യാപിക്കുന്നതാണ് ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സിന്റെ ഉപയോഗമേഖലകള്‍. വിനോദം, വ്യവസായം, ആരോഗ്യം, പ്രതിരോധം, ഭക്ഷ്യ സംസകരണം വാര്‍ത്താവിനിമിയം തുടങ്ങി ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സിന് എത്തിപ്പെടാന്‍ സാധിക്കാത്ത മേഖലകള്‍ വളരെ വിരളം.
നമ്മള്‍ക്കെല്ലാവര്‍ക്കും ചിരപരിചിതമായ ഇലക്ട്രോണിക് ഉപകരണമാണ് മൊബൈല്‍ ഫോണുകള്‍. വളച്ച് ചുരുട്ടി പോക്കറ്റില്‍ ഇടാവുന്ന ഒരു സമാര്‍ട്ട് ഫോണിനേക്കുറിച്ച് ചിന്തിച്ച് നോക്കൂ. ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സിന് ഇതെക്കെ വെറും നിസാരം. ഇലക്ട്രോണിക് ഉപകരണങ്ങളെ വളയ്ക്കാം, മടക്കാം, പേപ്പറുകള്‍ ചുരുട്ടി വയ്ക്കുന്നതുപോലെ ചുരുട്ടാം, ഇലാസ്‌ററിക് പോലെ വലിച്ച് നീട്ടാം ഇതൊക്കെ ഭാവിയില്‍ സാധാരണമാകാന്‍ പോവുകയാണ്.
ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സ് എന്നാല്‍ പുതിയ തരം സര്‍ക്യൂട്ട് രൂപകല്‍പ്പനയാണ്. സാധാരണ, സര്‍ക്യൂട്ടുകള്‍ എന്ന് പറഞ്ഞാല്‍ കുറെ കേബിളുകളും കണ്ടക്ടറുകളും നിറഞ്ഞ ഒരു ബോര്‍ഡാണ് നമ്മള്‍ക്ക് ഓര്‍മ്മ വരിക. എന്നാല്‍ ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സില്‍ സര്‍ക്യൂട്ടുകള്‍ പ് ളാസ്റ്റിക് പോലത്തെ പ്രതലത്തില്‍ പ്രിന്റ് ചെയ്യുകയാണ് ചെയ്യുക. പോളിഅമൈഡ്, പോളി എസ്റ്റര്‍ എന്നിവയിലാണ് ഇത്തരത്തില്‍ സര്‍ക്യൂട്ടുകള്‍ പ്രിന്റ് ചെയ്യുന്നത്. വെള്ളി ഉപയോഗിച്ചാണ് സര്‍ക്യൂട്ടുകള്‍ പ്രിന്റ് ചെയ്യുന്നത്.
കൂടാതെ വളരെ ചെറിയ, തലമുടി നാരിനേക്കാള്‍ കനം കുറഞ്ഞ കോപ്പര്‍ നാരുകള്‍ സര്‍ക്യൂട്ടുകളെ തമ്മില്‍ ബന്ധിപ്പിക്കാനായി ഉപയോഗിക്കുകയും ചെയ്യുന്നു. നാനോ ടെകനോളജിയുടെ വികാസമാണ് ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണികസിന്റെ അടിസ്ഥാനമായി വര്‍ത്തിക്കുന്നത്. കാര്‍ബണ്‍ നാനോട്യൂബുകള്‍ നാനോ ടെക്‌നോളജിയുടെ സംഭാവനയാണ്. കാര്‍ബണ്‍ നാനോട്യൂബുകള്‍ ഇപ്പോള്‍ ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സില്‍ ഉപയോഗിക്കാന്‍ ആരംഭിച്ചിട്ടുണ്ട്. ഇതിന്റെ ഗൂണമെന്തെന്നാല്‍ ഒരു സര്‍ക്യൂട്ടായി പ്രവര്‍ത്തിക്കുന്നതിനൊപ്പം ഉപകരണങ്ങളുടെ ഭാരം കുറയ്ക്കാനും 15 മടങ്ങ് വരെ അവയെ വലിച്ച് നീട്ടാനും സാധിക്കും.
സാധാണയായി എല്‍സിഡി നിര്‍മ്മാണത്തില്‍ ഗ് ളാസാണ് അടിസ്ഥാനമായി ഉപയോഗിക്കുന്നത്. എന്നാല്‍ ഇതിന് പകരമായി ഒരു പോളിമര്‍ ഫിലിം ഉപയോഗിച്ചാല്‍ ആ സംവിധാനമാകെ ഫ് ളെക്‌സിബിളാകും. ഒന്നിന് മീതേ മറ്റൊന്നായി പല അടരുകളായി ഫ് ളെക്‌സ് സര്‍ക്യൂട്ടുകള്‍ നിര്‍മ്മിക്കാനാകും. വളരെ ലളിതമായി പറഞ്ഞാല്‍ കംപ്യൂട്ടര്‍ കീബോര്‍ഡുകള്‍ക്ക് പകരമായി വര്‍ഷങ്ങള്‍ക്ക് മുമ്പ് രൂപംകൊണ്ട സ്വിച്ച് മാട്രികസ് കീ ബോര്‍ഡുകള്‍ ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സിന്റെ ലളിതമായ രൂപമാണ്.
പുതിയ സാങ്കേതികവിദ്യ വളരെ വലിയ ലോകമാണ് തുറന്ന് തന്നിരിക്കുന്നത്. കൈകളില്‍ പച്ചകുത്ത് (ടാറ്റൂ) പോലെ പതിപ്പിക്കാവുന്ന ഡിജിറ്റല്‍ വാച്ചുകള്‍, രോഗങ്ങളുണ്ടാകുമ്പോള്‍ നിറം മാറുന്ന സ്മാര്‍ട്ട് ടാറ്റൂകള്‍, ബാന്‍ഡുകള്‍ പോലെ കൈത്തണ്ടയില്‍ ചുറ്റിവയ്ക്കാവുന്ന ഉപകരണങ്ങള്‍ എന്നിവയൊക്കെ വിപണിയിലേക്ക് ഇറങ്ങാന്‍ പോവുകയാണ്.
ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സ് ഉപകരണങ്ങളെ വിപണിയില്‍ എത്തിക്കുന്നതില്‍ നിന്ന് ഇത്രയും കാലം തടഞ്ഞിരുന്നത് ഊര്‍ജസംഭരണ സംവിധാനങ്ങളുടെ അപര്യാപ്തതയായിരുന്നു.
എന്നാല്‍ ഫ് ളെക്‌സിബിള്‍ സോളാര്‍ പാനലുകളുടെ വരവോടെ പ്രതിസന്ധി ഏറെക്കുറെ ഒഴിവാകുമെന്ന് പറയാം. ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സ് അതിന്റെ ചിറക് വിരിച്ച് പറക്കാന്‍ പോകുന്നത് പ്രതിരോധമേഖലയിലാണ്. യുദ്ധമേഖലയിലോ, പ്രത്യേക സൈനിക നടപടിയിലോ ഏര്‍പ്പെട്ടിരിക്കുന്ന സൈനികരുടെ ഒരോ നീക്കവും അറിയാന്‍ അവരുടെ ശരീരത്തില്‍ സ്ഥാപിക്കുന്ന ഫ്‌ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സ് ഉപകരണങ്ങള്‍ കൊണ്ട് സാധിക്കും. മാത്രമല്ല അവരുടെ ശാരീരിക അവസ്ഥയെങ്ങനെ എന്നറിഞ്ഞ് ആവശ്യമായ വൈദ്യസഹായം ലഭ്യമാക്കാനും ഇത് സഹായിക്കും. ഭാരമൊട്ടും ഇല്ലാത്തതിനാല്‍ ഇത്തരം ഉപകരണങ്ങള്‍ സൈനികര്‍ക്ക് പ്രയാസങ്ങളുണ്ടാക്കുകയുമില്ല.
ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സ് രംഗത്തെ പ്രധാന കണ്ടുപിടുത്തമാണ് ഓര്‍ഗാനിക് ലൈറ്റ് എമിറ്റിമഗ് ഡയോഡുകള്‍ ( OLED ). ഇതും ഒരുതരം ലൈറ്റ് എമിറ്റിങ് ഡയോഡുകള്‍ അഥവാ എല്‍ഇഡിയാണ്. സാധാരണ എല്‍ഇഡികളായി പ്രവര്‍ത്തിക്കുന്നത് ചില അര്‍ധചാലകങ്ങളാണ്. അവയില്‍നിന്ന് വ്യത്യസ്തമായി വൈദ്യുതി പ്രവഹിക്കുമ്പോള്‍ പ്രകാശം പുറത്ത് വിടുന്ന ഓര്‍ഗാനിക് പദാര്‍ഥങ്ങളാണ്് ഒര്‍ഗാനിക് ലൈറ്റ് എമിറ്റിങ് ഡയോഡുകള്‍. സാധാരണ എല്‍ഇഡികളേക്കാള്‍ കനംകുറഞ്ഞതും ഫ് ളെക്‌സിബിളുമാണ്. ഫ് ളെക്‌സിബിള്‍ സോളാര്‍ പാനലുകള്‍ ഇതേ പാതയുടെ പിറവിയാണ്.
ഒഎല്‍ഇഡികളാണ് ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക് ഉപകരണങ്ങളുടെ ഡിസ്പ് ളേയായി പ്രവര്‍ത്തിക്കുന്നത്. ഇവ ഒരുതരം പോളിമറാണ്. പലനിറത്തിലുള്ള ഇത്തരം ഒഎല്‍ഇഡികളാണ് ഇനി ഭാവിയുടെ ദൃശ്യങ്ങളെ കാണിക്കുക. മാത്രമല്ല, ഇനി നമ്മള്‍ ധരിക്കാന്‍ പോകുന്ന വസ്ത്രങ്ങള്‍ പോലും ഫ് ളെക്‌സിബിള്‍ സാങ്കേതിക വിദ്യ സന്നിവേശിപ്പിച്ചതായിരിക്കും. കാര്യക്ഷമത,
കൂടുതല്‍ കാലം നിലനില്‍ക്കുന്നത്, കുറഞ്ഞ ഊര്‍ജ ഉപഭോഗം എന്നിവ ഫ് ളെക്‌സിബിള്‍ ഇലക്ട്രോണിക്‌സിന്റെ സവിശേഷതകളാണ്. അതുകൊണ്ട് തന്നെ ഇത് വിപളവം സൃഷ്ടിക്കുമെന്നതില്‍ സംശയം വേണ്ട.
ഫ് ളെക്‌സിബിള്‍ മൊബൈലുമായി സാംസങ്
സാംസങിന്റെ ജനപ്രിയ സ്മാര്‍ട്ട്‌ഫോണ്‍ ശ്രേണിയായ ഗാലക്‌സിയാണ് ഫ് ളെക്‌സിബിള്‍ ടെകനോളജിയുമായെത്താന്‍ പോകുന്നത്. ഫ് ളെക്‌സിബിള്‍ ഡിസ്‌പ്ലേയുടെ സാധ്യത സംബന്ധിച്ച് അന്വേഷിക്കുകയാണ് സാംസങെന്ന് കമ്പനിയിലെ ഇലക്‌ട്രോണിക്‌സ് വൈസ് പ്രസിഡന്റ് ഓഫ് ഡിസൈന്‍ ടീം ഡോംഗ് ഹൂണ്‍ ചാങ് സ്‌പെയിനിലെ ബാഴ്‌സലോണയില്‍ കഴിഞ്ഞ വര്‍ഷം നടന്ന മൊബൈല്‍ വേള്‍ഡ് കോണ്‍ഗ്രസില്‍ പറഞ്ഞിരുന്നു.
പ്രത്യേക തരം മെറ്റീരിയല്‍ ഉപയോഗിച്ചാണ് ഫോണ്‍ നിര്‍മിക്കുന്നതെന്ന് സാംസങ് കേന്ദ്രങ്ങള്‍ പറയുന്നു. 560 പിപിഐ റസല്യൂഷനോട് കൂടിയ 5 അല്ലെങ്കില്‍ 5.2 ഇഞ്ച് വലിപ്പമുള്ള സ്‌ക്രീനായിരിക്കും ഫോണിന് എന്നാണ് റിപ്പോര്‍ട്ടുകള്‍. 3 ജിബി റാം, 16 മെഗാപിക്‌സല്‍ ക്യാമറ, 4000 എംഎഎച്ച് ബാറ്ററി, ആന്‍ഡ്രോയിഡ് മാര്‍ഷ്മലോ പ്ലാറ്റ്‌ഫോം എന്നിവയായിരിക്കും ഫോണിലെന്നാണ് സൂചന

'വൈഫൈ'യുടെ 100 മടങ്ങ് വേഗമുള്ള 'ലൈഫൈ' പരീക്ഷിച്ചു ഭാവിയില്‍ എല്‍ഇഡി ബള്‍ബുകള്‍ വെളിച്ചത്തിന് മാത്രമുള്ളതാകില്ല, ഇന്റര്‍നെറ്റ് ലഭ്യമാക്കാനുള്ള ഉപകരണങ്ങള്‍ കൂടിയാകും

'വൈഫൈ'യുടെ 100 മടങ്ങ് വേഗമുള്ള 'ലൈഫൈ' പരീക്ഷിച്ചു
ഭാവിയില്‍ എല്‍ഇഡി ബള്‍ബുകള്‍ വെളിച്ചത്തിന് മാത്രമുള്ളതാകില്ല, ഇന്റര്‍നെറ്റ് ലഭ്യമാക്കാനുള്ള ഉപകരണങ്ങള്‍ കൂടിയാകും
'വൈഫൈ'ക്ക് പകരം ദൃശ്യപ്രകാശത്തിന്റെ സഹായത്തോടെ ഡേറ്റാ കൈമാറ്റം സാധ്യമാക്കുന്ന 'ലൈഫൈ' ( Li-fi ) സംവിധാനത്തിന്റെ പരീക്ഷണ ഉപയോഗം തുടങ്ങി. ഒരു ഓഫീസില്‍ ലൈഫൈ പരീക്ഷണാര്‍ഥം ഉപയോഗിച്ചു.
പരമ്പരാഗത വൈഫൈ സംവിധാനത്തെ അപേക്ഷിച്ച് നൂറുമടങ്ങ് വേഗത്തില്‍ ഡേറ്റാ കൈമാറാന്‍ ലൈഫൈ സഹായിക്കും. സെക്കന്‍ഡില്‍ 1ഗിഗാബിറ്റ് വേഗത്തില്‍ (1Gbps ) ഡേറ്റാ കൈമാറ്റം സാധ്യമാക്കാന്‍ ലൈഫൈയ്ക്ക് കഴിയും.
സാധാരണ എല്‍ഇഡി ബള്‍ബ് പോലൊരു പ്രകാശ സ്രോതസ്സും ഒരു ഇന്റര്‍നെറ്റ് കണക്ഷനും ഒരു ഫോട്ടോ ഡിറ്റെക്ടറും മതി പുതിയ സംവിധാനത്തില്‍.
എസ്‌തോനിയന്‍ തലസ്ഥാനമായ ടാലിനില്‍, 'വെല്‍മിന്നി' ( Velmenni ) എന്ന കമ്പനിയാണ് ലൈഫൈ സംവിധാനം ഓഫീസിനുള്ളില്‍ പരീക്ഷിച്ചത്. 'വിസിബിള്‍ ലൈറ്റ് കമ്മ്യൂണിക്കേഷന്‍' ( VLC ) രംഗത്ത് മുന്നേറ്റം സാധ്യമായതായി കമ്പനി അറിയിച്ചു. 'വെല്‍മിന്നി ജുഗ്നു' ( Velmenni Jugnu ) എന്നാണ് കമ്പനി ഇതിന് പേര് നല്‍കിയിട്ടുള്ളത്. ന്യൂഡല്‍ഹി കേന്ദ്രമായുള്ള കമ്പനിയാണ് വെല്‍മിന്നി.
Velmenni Jugnu
ലൈഫൈ എനേബിള്‍ ചെയ്തിട്ടുള്ള ലൈറ്റ് ബള്‍ബിന്റെ സഹായത്തോടെ 1Gbps ഡേറ്റ വേഗം കൈവരിക്കാന്‍ വെല്‍മെന്നിക്കായി. സൈദ്ധാന്തികമായി ഈ വേഗം 224 Gbps വരെയാകാമെന്ന് ലബോറട്ടറി ടെസ്റ്റുകളില്‍ കണ്ടിട്ടുണ്ട്.
വെല്‍മിന്നി ഓഫീസില്‍ നടന്ന ടെസ്റ്റില്‍ ജീവനക്കാര്‍ക്ക് ലൈഫൈ വഴി ഇന്റര്‍നെറ്റ് ഉപയോഗിക്കാന്‍ കഴിഞ്ഞു.
'ദൃശ്യപ്രകാശമുപയോഗിച്ച് ഡേറ്റ കൈമാറ്റം സാധ്യമാക്കുന്ന അടുത്ത തലമുറ എല്‍ഇഡി ബള്‍ബുകളാണ് ജുഗ്നു' -കമ്പനിയുടെ വെബ്ബ്‌സൈറ്റ് പറയുന്നു. 'ലൈഫൈ ടെക്‌നോളജി ഞങ്ങള്‍ പുതിയ റേഞ്ച് എല്‍ഇഡികളില്‍ ഏര്‍പ്പെടുത്തുകയാണ്'.
പുതിയ പരീക്ഷണം കൂടുതല്‍ സ്ഥലങ്ങളില്‍ വിജയിച്ചാല്‍, ഭാവിയില്‍ എല്‍ഇഡി ബള്‍ബുകള്‍ വെളിച്ചത്തിന് മാത്രമുള്ളതാകില്ല, ഇന്റര്‍നെറ്റ് ലഭിക്കാനുള്ള ഉപാധി കൂടിയാകും.
'മൂന്നോ നാലോ വര്‍ഷത്തിനകം' ഈ സാങ്കേതികവിദ്യ ഉപയോക്താക്കളുടെ പക്കലെത്തുമെന്ന്, വെല്‍മിന്നി കമ്പനിയുടെ ചീഫ് എക്‌സിക്യുട്ടീവ് ദീപക് സൊലാങ്കി 'ഇന്റര്‍നാഷണല്‍ ബിസിനസ് ടൈംസി'നോട് പറഞ്ഞു.
സാങ്കേതികരംഗത്ത് വര്‍ഷങ്ങളായി ഉയര്‍ന്ന് കേര്‍ക്കുന്ന പേരാണ് 'ലൈഫൈ' എന്നത്. 2011ല്‍ എഡിന്‍ബറോ സര്‍വകലാശാലയിലെ പ്രൊഫ.ഹരോള്‍ഡ് ഹാസ് ഒരു ടെഡ് ( TED - Technology, Entertainment and Design ) പ്രഭാഷണത്തിലാണ് പ്രകാശമുപയോഗിച്ച് ഡേറ്റ കൈമാറാനുള്ള വിദ്യ ആദ്യം ലോകത്തിന് മുന്നില്‍ കാട്ടിയത്.
യുട്യൂബില്‍ ഇതിനകം ലക്ഷക്കണക്കിനാളുകള്‍ കണ്ടുകഴിഞ്ഞ ആ വീഡിയോയില്‍, ഒരു എല്‍ഇഡി ലൈറ്റുപയോഗിച്ച് വീഡിയോ സ്ട്രീം ചെയ്ത് അദ്ദേഹം കാട്ടുന്നുണ്ട്. ഭാവിയില്‍ ലക്ഷക്കണക്കിന് ലൈറ്റ് ബള്‍ബുകള്‍ക്ക് വയര്‍ലെസ്സ് ഹോട്ട്‌സ്‌പോട്ടുകളായി മാറാന്‍ കഴിയുമെന്ന് പ്രൊഫ.ഹാസ് പ്രവചിക്കുകയും ചെയ്തു.
റേഡിയോ തരംഗ വര്‍ണരാജി (റേഡിയോ സ്‌പെക്ട്രം) അല്ല ലൈഫൈ ഉപയോഗിക്കുന്നത്. ദൃശ്യപ്രകാശ വര്‍ണരാജിയാണ്. അതിനാല്‍, വിമാനങ്ങള്‍ക്കുള്ളിലും മറ്റും ലൈഫൈ ഉപയോഗിക്കുന്നതിന് തടസ്സമുണ്ടാകില്ല എന്നതാണ് ഈ സങ്കേതത്തിന്റെ ഒരു പ്രയോജനം.

What's a Retina display? What's a Retina HD display? Which Apple devices have Retina displays? And are they worth the money?

What's a Retina display? What's a Retina HD display? Which Apple devices have Retina displays? And are they worth the money?
Retina displays - and, more recently, Retina HD displays - are often mentioned in discussions of Apple products. In this beginner's guide to Retina and Retina HD, we explain the definition of a Retina display, the difference between Retina and Retina HD displays, which iPads, iPhones, iPods, Macs and MacBooks have Retina or Retina HD displays, their pros and cons, the premium you are likely to pay for Retina screens where non-Retina options are available and whether (in our opinion) they are worth the extra money.
What's a Retina display? Or rather, what's the precise definition of a Retina display?
A Retina display is more of a proprietary, Apple-specific marketing term than a precise technical term, but there is a definition: it refers to a screen on a computing device that has a high enough pixel density that the human eye can't make out individual pixels - or a general 'pixellation' effect - at all. In other words, the human eye is scientifically incapable of telling the difference between a photo of a painting shown on a Retina display, and the painting itself - in theory, anyway.
As mentioned, Retina displays are proprietary to Apple. So while a rival company could produce a screen to the same specs, it wouldn't be referred to with the same word. It's an Apple-trademarked term.
Retina display: iPad Air
My eye won't be fooled.
Perhaps not. Apple was able to wheel out some scientific backing for its claims when launching the Retina display, but it has been suggested that people with better than 20/20 vision might be able to pick out the pixels.
Furthermore, Apple's later launching of devices with better-than-Retina resolution (under the term 'Retina HD', which we'll discuss in due course) rather undermines its claim that Retina is as sharp as the human eye can make out.
What resolution does a Retina display have?
That varies. Screen resolutions are given in the format '[number of pixels] x [number pf pixels', but the key factor in classifying a screen as Retina is pixel density, not the overall number of pixels. This makes sense, if you think about it: if you spread the same number of pixels across a larger screen, it will obviously be easier for the eye to pick out individual pixels. Pixel density is given as a single figure, measured in pixels per inch, or ppi.
And even in terms of pixel density there isn't a single figure that qualifies as Retina, since the equation also takes into account the distance of the screen from the eye. The required pixel density for each type of computing device - smartphone, tablet, laptop, desktop PC - is calculated based on a typical viewing distance. If you hold your iPad right up next to your face (you shouldn't do that, by the way) you may find that you can pick out pixels after all, because you are no longer using the device at the expected typical disance. Don't expect a refund.
The pixel density figures are: 326ppi (pixels per inch) for smartphones, since they are expected to be held the closest to the face; 264ppi for tablets; and 220ppi for laptops.
Are there better screens than Retina displays?
Yes there are. At any rate, there are screens out there offering a higher pixel density in the various categories listed above. Most obviously, since the iPhone 6 launch, Apple itself offers an upgraded class of screens that it calls 'Retina HD'. But many Android devices surpass not only the Retina screens but even the Retina HD models. The LG G3, for instance, has a flabbergasting pixel density of 534ppi, which blows even the iPhone 6 Plus out of the water.
Of course, it's worth pointing out that, according to our previous definition of Retina, it's debatable whether increasing the resolution/pixel density beyond Retina levels really produces a 'better' display. After all, what's the point in making a screen sharper if the human eye is no longer noticing any difference?
(Some would argue that, in moving up to a higher pixel density with the iPhone 6 Plus - as we shall see shortly - Apple made a tacit acknowledgement that a higher pixel density can be perceived by the human eye. Another possibility is that Apple simply didn't want rival device makers boasting about their superior screens, that no one can really tell the difference between 401ppi and 534ppi, and that we are all pretending the emperor is wearing clothes.)
Okay, what about a Retina HD display? What the difference between Retina and Retina HD?
The term Retina HD display - so far - refers only to the screens on the iPhone 6 and iPhone 6 Plus, although it seems almost certain that the iPhone 6s or iPhone 7 will boast similar specs - and perhaps 2015 will be the year that Apple extends the Retina HD branding to the iPad line. The iPad Pro, for one, would benefit from the cachet and differentiation that Retina HD would offer, but the iPad Air 3 and iPad mini 3 are also possibilities.
But what is the definition of Retina HD? This appears to be a bit woolier than Retina.
Apple insists that both the iPhone 6 and the iPhone 6 Plus have Retina HD displays, even though they have different resolutions and different pixel densities from one another. The iPhone 6, indeed, has the same as the plain old Retina displays on the iPhone 5s et al, so we know that pixel density isn't the defining difference between Retina and Retina HD.
Retina HD display: iPhone 6
So what is the difference between Retina and Retina HD? Apple has been a little vague on this, but it appears to refer to resolution rather than pixel density, meaning that bigger (but not necessarily sharper) screens qualify.
When it comes to the subjective experience of sharpness, pixel density is the key factor, not resolution. The iPhone 6 has a higher resolution than any previous Apple smartphone - 1334 × 750 - but this is because it has a larger screen than any previous Apple smartphone. (Its pixel density is the same as every previous iPhone since the iPhone 4.)
The iPhone 6 Plus, whose screen is bigger still, has a giant resolution of 1920 × 1080. But in this case the pixel density is bigger too - the extra pixels, in effect, exceed the extra screen space in which they are squeezed - meaning Apple's phablet is sharper than any other Apple smartphone. This, we would argue, is the sort of quality that is implied by the term 'Retina HD', but the fact that the iPhone 6 qualifies too shows this not to be the case.
What else does Retina HD refer to? It's possible that Apple intends the term to encompass the other new developments seen in the iPhone 6-series handsets:
Higher contrast: I'm using Apple's own words here, but apparently the manufacturing method "involves using UV light to precisely position the displays liquid crystals so they lie exactly where they should. Better-aligned crystals deliver a superior viewing experience, with deeper blacks and sharper text."
Dual-domain pixels: Apple claims that these enable the iPhone 6 and 6 Plus to offer wider viewing angles. We're not sure; perhaps the iPhone 6 can be viewed when slightly flatter on to the eye than the 5-series, but it's hard to notice much of a difference.
Improved polariser: Pretty niche stuff, this. You can more easily view what's on the Retina HD display when wearing sunglasses. (We tested this out on Macworld's balcony and it's true that icons are indisuptably clearer and brighter when viewed through sunglasses on an iPhone 6 than on earlier devices.) Could come in handy in the summer.
How do Apple's non-Retina displays compare with its Retina displays?
Obviously this depends on the resolution, pixel density and so on of the non-Retina display, but it's a fairly safe bet that Apple will never sell a computing device with a fuzzy or unclear screen.
If you compare non-Retina and Retina iPad displays you can see there is a difference, but the non-Retina display is still good. If you hadn't tried a Retina display, you'd probably think it was great.
The main difference is noticeable on fine detail and text. But you will occasionally be able to pick up the pixellation effect - only slightly, but it is there.
Which Apple products have got Retina displays?
Here are the product areas where Apple offers Retina displays, alongside any non-Retina alternative(s):
iPad mini 2: Retina display. From £239 with 16GB.
iPad mini 3: Retina as well. From £319 with 16GB.
iPad Air: Retina. From £319 with 16GB.
iPad Air 2: Retina. From £399 with 16GB.
In other words, all four iPads have Retina displays (but none have Retina HD). Apple discontinued its only remaining non-Retina iPad - the iPad mini 1 - earlier in 2015, although you may be able to find a second-hand or refurbished model.
As with the iPads, there are no non-Retina options here: all iPhones currently available have at least Retina displays. The concept was introduced with the iPhone 4, and was also present on the iPhone 4s and iPhone 5.
Of the four iPhone models currently available, the iPhone 5s (Apple Shop link) and iPhone 5c (Apple Shop link) both have Retina displays, whereas the iPhone 6 and iPhone 6 Plus (Apple Shop link for both models) both have Retina HD displays.
MacBook laptop
12in MacBook: Retina (from £1,049).
MacBook Pro laptops
13in MacBook Pro: non-Retina (from £899).
13in MacBook Pro with Retina display: Retina (from £999).
15in MacBook Pro with Retina display: Retina (from £1,599).
The non-Retina MacBook Pro is £100 cheaper than its approximate Retina equivalent, but in this case the comparison is difficult: the non-Retina model is much older and has numerous differences other than the displays. (It has a hard drive rather than flash storage, for instance.)
MacBook Air laptops
All of Apple's MacBook Air laptops are non-Retina. But there is a persistent rumour that a Retina MacBook Air will launch in the near future.
21in iMac: non-Retina (from £899).
27in iMac: non-Retina (from £1,449).
27in iMac with Retina 5K display: Retina (the clue's in the name...). From £1,599.
Adding a Retina display to your iMac adds £150 to your bill.
Are the Retina and Retina HD displays worth the extra money?
Let's start with plain old Retina.
For certain tasks, Retina screens are absolutely worth the money (although by this point you may well find that non-Retina alternatives are getting thin on the ground). If you're going to use your iPad mini for reading ebooks, for instance, you'll really benefit from a sharper screen. And if you edit photos on your laptop, they'll look a lot better in Retina form.
Bear in mind, too, that the price differences above don't just reflect the inclusion of a Retina display. The iPad mini 2 has a more powerful processor that the non-Retina iPad mini 1, for example, so it's much more future-proofed for handling apps and games in the future. Of course, the original iPad mini is no longer available from Apple, so you may find when searching for a second-hand or refurbished model that it's therefore cheaper still, and may tempt you for that reason.
Check out the individual reviews for more information, and since eyesight is an entirely personal thing, we'd recommend going into an Apple store, or checking out a friend's Retina and non-Retina devices (side by side if possible) to see the difference for yourself. You may not even notice one, in which case your buying decision just got easier.
What are Retina and Retina HD displays, and are they worth the money?
What about Retina HD? That's harder to quantify, since the iPhone 6 and iPhone 6 Plus are such different propositions. They're lovely screens, for sure, but the main thing they offer over their non-Retina predecessors is size. The iPhone 6 Plus is super, super sharp, but the iPhone 6 has the same pixel density as the iPhone 5s.
Other than the higher resolution that comes with the larger screens, our (totally subjective) feeling is that the additional 'Retina HD' criteria mentioned above are the least of the reasons why you'd be upgrading from your iPhone 5s - the polariser is quite nice for sunny days, the viewing angles seem to be very slightly better but will hardly affect your day-to-day experience, and the improved contrast hasn't blown us away. But then, the improved camera, bigger screen, redesigned chassis and Apple Pay will be what most potential upgraders are interested in, not the differences between Retina and Retina HD.